The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 01, 2009
Filed:
May. 02, 2006
Alexander Wayne Hietala, Phoenix, AZ (US);
Ryan Lee Bunch, Greensboro, NC (US);
Scott Robert Humphreys, Greensboro, NC (US);
Barry Travis Hunt, Jr., Greensboro, NC (US);
Stephen T. Janesch, Greensboro, NC (US);
Alexander Wayne Hietala, Phoenix, AZ (US);
Ryan Lee Bunch, Greensboro, NC (US);
Scott Robert Humphreys, Greensboro, NC (US);
Barry Travis Hunt, Jr., Greensboro, NC (US);
Stephen T. Janesch, Greensboro, NC (US);
RF Micro Devices, Inc., Greensboro, NC (US);
Abstract
A fractional-N based Automatic Frequency Control (AFC) system for a mobile terminal is provided. In general, automatic frequency control is implemented in a frequency synthesizer to correct or compensate for a frequency error of an associated reference oscillator. The frequency synthesizer includes a first fractional-N phase-locked loop (FN-PLL) generating a baseband clock signal used by a baseband processor of the mobile terminal, a second FN-PLL generating a receiver local oscillator signal used by a receiver of the mobile terminal to downconvert a received radio frequency signal to a desired frequency, and a translational PLL generating a transmitter local oscillator signal used by a transmitter of the mobile terminal to provide a radio frequency transmit signal. The automatic frequency control is performed by applying a digital correction value, which is preferably multiplicative, to fractional-N dividers of the first and second FN-PLLs.